High strength composite wall panel system

ABSTRACT

The present invention is directed to improved composite action walls having an insulation wythe sandwiched between structural wythes. The structural wythes provide the load-bearing function and prevent the collapse of the wall under high wind loads. The structural wythes demonstrate composite action existing between the structural wythes such that an improved, stronger and less expensive wall may be constructed. The present invention is also directed to an insulation wythe, which is useful in the composite action wall of the present invention, having grooves formed therein such that the material of the structural wythes flow into the groove to form a mechanical bond between the structural wythes and the insulation wythe. The walls of the present invention are simple to manufacture and provide a verifiable and consistent composite action between about 50% to about 100% composite action.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention relates to the field of concrete wall structuresand, more specifically, to the field of high composite action wallstructures.

BACKGROUND OF THE INVENTION

In the area of building and construction, concrete wall panels have beenfabricated and then coated or layered with insulation having relativelylow strength to provide a well-insulated wall structure having highstrength. Typically, a structural wall is built and insulation isapplied when finishing the wall. The insulation inhibits the flow ofthermal energy through the wall.

A commonly used measurement of the thermal insulating qualities of amaterial is the mathematical coefficient “R”, which is a measure of thethermal resistance of a material. The coefficient R is equal to thethickness divided by the thermal coefficient “K”. A high R valueprovides a high degree of high thermal resistance or insulating ability.

Concrete, formed of hydraulic cement binder, water and aggregate is arelatively high strength, low cost building material. Unfortunately,concrete has the drawback of offering a poor K value and thus provideslittle thermal insulation. An 8 inch slab of concrete has an R value ofapproximately 0.64; a 1 inch panel of polystyrene foam has an R value ofapproximately 5; and a 3.5 inch layer of glass fiber building insulationprovides an R value of approximately 13. Polystyrene and fiberglassprovide a high R value but offer little or no structural strength.

Often walls are built with a structural layer that has a decorativewythe fixed to the outer or inner surface. The wythes typically includean intermediate space that can be fitted or retrofitted with any numberof insulating materials, including fiberglass or polystyrene foams. TheR-value of insulated two wythe walls is limited due to the structuralbridging between the outer and inner wall. The structural bridgingprovides high strength and integrity and prevents the walls fromcollapsing. Structural bridges are typically metal studs, bolts, orbeams. The structural bridges also serve as thermal bridges because themetal allows a thermal short bypassing the insulation. These thermalbridges cause the R-value of the constructed wall to be substantiallylower than the R-value of the insulation wythe. U.S. Pat. No. 4,393,635to Long, U.S. Pat. No. 4,329,821 to Long et al., U.S. Pat. No. 2,775,018to McLaughlin, U.S. Pat. No. 2,645,929 to Jones, and U.S. Pat. No.2,412,744 to Nelson disclose wall structures held together using metaltie rods or studs.

U.S. Pat. No. 4,829,733 to Long provides a plastic tie for forming aninsulated wall having inner and outer concrete structural wythes withhighly insulating wythes therebetween. The plastic tie is used in theconstruction industry, but is relatively expensive and difficult tomanufacture and does not provide adequate composite action.

Composite action describes how well a multi-layered panel, or compositewall, transfers shear forces between its different wythes and istypically identified as a percentage between 0% and 100%. High compositeaction results in the transfer shear forces between the structuralwythes so that the composite wall will have a moment of inertiaapproaching that of a solid wall having the overall thickness of a threewythe wall. Low composite action does not transfer shear forces and thewall will have a moment of inertia approaching that of the sum ofmoments of inertia of the individual wythes. Composite action providesstructural integrity to the wall. Composite action is highly desirablebecause it strengthens the wall against the forces of the wind andreduces deflection of the wall. A high composite action wall can also bedesigned to meet code requirements while reducing the mass and cost ofthe wall. Accordingly, it is generally desirable to produce compositewalls having high composite action so that they will remain intact whenloads are applied to a wall. Existing connectors, however, have thus farproven inadequate for providing composite walls with the desiredcomposite action. Although Composite Technologies Corporation, theassignee of the Long '733 Patent, has made the claim that some of itsconnectors are able to provide 40% to 60% composite action, independenttesting has shown that such connectors only provide about 10% compositeaction.

Insulated walls generally include an insulation wythe sandwiched betweena structural wythe and a fascia wythe. The structural wythe is typicallyused as the load-bearing member of the wall. The fascia wythe istypically not used to bear a load separated from the structural wythebecause of insufficient composite action existing between the faciawythe and the structural wythe. However, if the composite action of thewall was sufficiently high, e.g., between 60% to 100%, the fascia wythecould potentially be used to bear a substantial portion of the overallload.

Accordingly, there is currently a need in the art for insulatingcomposite walls with high composite action.

SUMMARY OF THE INVENTION

The present invention is directed to improved composite action wallshaving an insulation wythe sandwiched between structural wythes. Thestructural wythes provide the load-bearing function and prevent thecollapse of the wall under high wind loads. The structural wythesdemonstrate composite action existing between the structural wythes suchthat an improved, stronger and less expensive wall may be constructed.The present invention is also directed to an insulation wythe, which isuseful in the composite action wall of the present invention, havinggrooves formed therein such that the material of the structural wythesflow into the groove to form a mechanical bond between the structuralwythes and the insulation wythe.

The walls of the present invention are simple to manufacture and providea verifiable and consistent composite action between about 50% to about100% composite action, preferably at least about 60% composite action,more preferably at least about 70% composite action, more especiallypreferably at least about 80% composite action, and most preferably atleast about 90% composite action. The degree of composite action and thestrength of the wall is improved by the structure of a composite actiontie between first and second structural wythes and an insulation wythetherebetween

One of ordinary skill in the art will be able to, based on the strengthand composite action of the connectors, the strength and thickness ofthe structural wythes, the strength and thickness of the insulatingwythe, and other factors that may be determined to affect overallcomposite wall action, design a spacing pattern that will provide thedesired composite action.

These and other benefits, advantages and features of the presentinvention will become more fully apparent from the following descriptionand appended claims, or may be learned by the practice of the inventionas set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the connector of the invention;

FIG. 2 is a perspective view of another alternative embodiment of theconnector of the invention;

FIG. 3A is a plan view of an insulating wythe having a groove patternthat may be used in the composite wall structure of the presentinvention;

FIG. 3B is a plan view of an insulating wythe having a groove patternthat may be used in the composite wall structure of the presentinvention;

FIG. 3C is a plan view of an insulating wythe having a groove patternthat may be used in the composite wall structure of the presentinvention;

FIG. 4A is a cross-sectional view of an insulating wythe showing agroove structure that may be used as the insulating wythe of the presentinvention;

FIG. 4B is a cross-sectional view of an insulating wythe showing anothergroove structure that may be used as an insulating wythe of the presentinvention;

FIG. 5A is a cross-sectional view of a partially completed compositewall structure incorporating the connector illustrated in FIGS. 1 and 2;

FIG. 5B is a cross-sectional view of a completed composite wallstructure incorporating the connector illustrated in FIGS. 1 and 2.

FIG. 6 is a graphical illustration showing the deflection in the wallpanel system including the connector of the present invention; and

FIG. 7 is a perspective view of an alternative embodiment of theconnector of the invention.

DETAILED DESCRIPTION AND PREFERED EMBODIMENTS OF THE INVENTION

A detailed description of the connectors of the invention will now beprovided with specific reference to figures illustrating variousembodiments of the invention. It will be appreciated that likestructures will be provided with like reference designations.

The embodiments of the present invention are generally directed toimproved connectors used for the manufacture of insulating compositewalls that include an insulation wythe sandwiched between two wythes ofhardenable structural material. The connectors are specificallyconfigured to secure the two wythes of structural material against theinsulation wythe and to provide the resultant composite wall with fromabout 50% to 100% composite action.

The term “composite action,” which is well term known in the art,generally refers to the ability of a composite wall to act like a singlelaminated wall rather than like a wall having a plurality ofdisconnected wythes. The following equation is used by the concreteindustry (PreCast/Prestressed Concrete Institute (PCI)) to definecomposite action as a percentage, within a range of 0% to 100%:k=(I_(exp)−I_(nc))/(I_(c)−I_(nc)), wherein I_(exp) is the experimentallydetermined moment of inertia of the test wall and I_(nc) and I_(c) arethe respective theoretical values of the moments of inertia of the 0%composite action wall and of the 1000% composite action wall.

Hardenable structural materials may be any material that is configuredto change from an unhardened state, in which the material is generallycharacterized as uncured, deformable, or fluid, to a hardened state, inwhich the material is generally characterized as cured or solid. Oneexample of a hardenable structural material includes concrete materialincluding a hydraulic cement binder, water, an aggregate material andother appropriate admixtures. Other examples of the hardenablestructural material include plasters, mortars, plastics, and resins.Hardenable structural materials when in a solid state may be usedinterchangeably with the term “structural material.”

The insulation material is typically extruded polystyrene, differentversions, sizes and thicknesses of which are distributed by OwensCorning of Toledo, Ohio under the FOAMULAR trademark. However, the useof other foams is possible, such as expanded polystyrene foam,polyurethane foam, polypropylene foam, polyisocyanate foam,polyisocyanurate foam, and combinations thereof.

Insulating composite walls are typically walls or other layeredstructures that include one or more insulation wythes disposed betweenwythes of structural material. Insulating composite walls are generallyformed of three wythes; each of these wythes may also include aplurality of layers.

The connectors of the invention are preferably injection molded from anyappropriate resin or other high strength plastic material, although theymay also be molded by resin transfer molding, reaction injectionmolding, or any other single step or relatively simple molding processknown in the art. It is also within the scope of the invention toutilize multi-step manufacturing processes, such as those that employassembly and/or machining steps.

A preferred resinous material is polyphthalamide (PPA) resin because ofthe ease in which it may be injection molded. Other similar resinousmaterials include a polycarbonate resin and a polycarbonate-polybutyleneterephthalate alloy, which are generally less expensive thanpolycarbonate resins. Other resins that may be used to manufacture theconnectors of the invention include, but are not limited to, epoxyresins and thermoset plastics. Other high strength, high R-valuematerials may also be used. The high R value generally minimizes thetransfer of heat between the two wythes of the structural material inthe composite wall that occurs through the connectors.

Although not necessary in many instances, it may be desirable toincorporate within the resinous material or other plastic materialfibers such as glass fibers, carbon fibers, boron fibers, ceramicfibers, and the like in order to increase the tensile strength, bendingstrength, shear strength and toughness of the connectors.

FIGS. 1 and 2 illustrate the connector of the present invention,sidewalls 14 a and raised longitudinal ribs 15 a generally terminatewithin the first segment 20 a into corresponding pointed tips 27 a. Thisconfiguration of pointed tips 27 a is particularly suitable forfacilitating the insertion of the connector 10 a through the insulationwythe of a composite wall. The connectors 10 a of the invention mayinclude a trailing wall 40 a that extends at least partially between thesidewalls 14 a within the trailing segment 22 a. It will be appreciatedthat the wall 40 a may be formed in any desired shape according to theinvention. FIG. 1 shows a trailing wall 40 a that is generallyrectilinear with rounded edges and corners, while FIG. 2 shows atrailing wall 40 b that includes recessed portions along its length tofacilitate gripping by a user. One use of the trailing wall 40 a, 40 bis for gripping the connector 10 a. The wall 40 a, 40 b can also be usedfor receiving a driving force sufficient for driving the connector 10 athrough the insulating wythe of a composite wall. Yet another functionof the wall 40 a, 40 b is to provide an anchor for securing the secondsegment within a wythe of structural material. For instance, theprotrusion of the wall 40 a, 40 b may be used as an anchor for securingthe connector 10 a within a wythe of structural material during themanufacture of a composite wall, as described below.

FIG. 7 illustrates an alternative embodiment of the present invention.The pointed tips 100 are larger than the leg portions 102 a, 104 a. Thisfacilitates better insertion of the connector 10 a through theinsulation wythe of a composite wall.

The connectors illustrated in FIGS. 1 and 2 include a structure fororienting the connectors within the insulating wythe of a composite walland at a predetermined depth. The connector may be oriented by a flange44 a affixed to and protruding away from the sidewalls 14 a at theintersection of the second segment 22 a and the mesial segment 24 a. Theflange 44 a is specifically configured to engage the insulating wythe ofa composite wall to prevent the second segment 22 a from passing throughthe insulating wythe.

The connector embodiments illustrated in FIGS. 1 and 2 also may includeone or more recesses 45 a formed between pointed tips 27 a. Recesses 45a allow reinforcement (e.g. rebar) that may be present in the firststructural wythe to be inserted into the recesses 45 a between thepointed tips 26 a. In addition recesses 45 a may increase the compositeaction of the connector.

FIGS. 5A and 5B show how the connectors 10 a can be used to manufacturea composite wall. The use of connectors 10 a will be described in detailhereinafter. In a preferred method for manufacturing composite wallstructures, a first wythe 60 of a structural material is poured into anappropriate form (not shown). In general, the first structural wythewill be a rectangular slab, although it may also include other design,ornamental or structural features. The only limitation is that it have athickness or depth great enough to give the first structural wythe 60adequate strength and the ability to firmly anchor the penetratingsegment 20 of the connector 10 a therein.

Before the first structural wythe 60 obtains such rigidity that aconnector 10 a cannot be inserted therein without damaging the ultimatestructural integrity and strength of the first structural wythe 60, aninsulating wythe 70 is placed adjacent to the exposed side of the firststructural wythe 60. The insulating wythe 70 may, although notnecessarily, include a plurality of holes or slots through which theconnectors of the invention may be inserted.

The connector 10 a is then pushed or driven through the insulation wythe70 and into the first structural wythe 60 while the structural materialis still unhardened. The tapered end 26 on the connector 10 a isconfigured to facilitate passage of the connector 10 a through anypreformed holes or to cut through the insulation when there are not anypreformed holes in the insulation wythe, thereby facilitating theinsertion of the connector 10 a in either event. In order to insert theconnector 10 a to a desired depth, it may be necessary to apply adriving force to the wall 40 of the connector 10 a. This driving forcemay be applied by hand or with a tool, such as a hammer or mallet. Theconnector 10 a is inserted to the insulation wythe 70 until the flange44 protruding away from the web portion 16 engages against theinsulation wythe 70, thereby indicating the desired depth has beenreached. Accordingly, the flange 44 may be formed of any suitablestructure for orienting the connector 10 a within the insulation wythe70 at a predetermined depth.

Once the connector 10 a is properly oriented within the insulation wythe70, the structural material of the first structural wythe 60 flows intoand engages hole formations 46 or other anchor of the first segment 20of the connector 10 a. The structural material also flows into groove 72formed in insulation wythe 70. Vibration of the structural wythe 60and/or movement of the insulation wythe 70 or connector 10 a may benecessary to ensure adequate engagement of the groove 72 and penetratingsegment 20 with the structural material. Once the structural materialcures, the connector 10 a is effectively anchored within the firststructural wythe 60 and the insulation wythe 70 is anchored to thestructural wythe 60 by groove 72.

After the first structural wythe 60 has achieved an adequate level ofhardness or strength, a second wythe of structural material is pouredover the surface of the insulating wythe 70 to form the secondstructural wythe 80, as shown in FIG. 4B. The depth of the secondstructural wythe 80 should be such that it completely, or at leastsubstantially, engulfs the head 40 of the connector and engages anyanchor formed in the second segment 22 of the connector 10, therebyproviding an adequate anchoring effect of the connector 10 within thesecond structural wythe 22. The material of structural wythe 80 flowsinto groove 72 to anchor structural wythe 80 to insulation wythe 70. Theflange 44 also aids in preventing the hardened second structural wythe80 from collapsing against the first structural wythe 60 when hardenedand tilted up or otherwise positioned for use.

FIG. 4B shows the use of keyhole or truncated tear drop shaped grooves72 formed on the major surfaces of the insulating wythe 70. The materialof the structural wythes 60, 80 flows into grooves 72 and forms amechanical bond between the structural material 60 and the insulationwythe 70. Grooves on opposite major surfaces of the insulation wythe 70may be formed congruently, as shown in FIG. 3B or may be offset orstaggered as shown in FIGS. 9A-9C.

FIGS. 6A and 6B illustrate a preferred method for manufacturingcomposite wall structures using connectors 10 a of FIGS. 6 and 7. Afirst wythe 60 of a structural material is poured into an appropriateform (not shown). In general, the first structural wythe will be arectangular slab, although it may also include other design, ornamentalor structural features. The only limitation is that it have a thicknessor depth great enough to give the first structural wythe 60 adequatestrength and the ability to firmly anchor the penetrating segment 20 aof the connector 10 a therein.

Before the first structural wythe 60 obtains such rigidity that aconnector 10 a cannot be inserted therein without damaging the ultimatestructural integrity and strength of the first structural wythe 60, aninsulating wythe 70 is placed adjacent to the exposed side of the firststructural wythe 60. Vibration of the structural wythe 60 and/ormovement of the insulation wythe 70 or connector 10 a may be necessaryto ensure adequate engagement of the groove 72 and penetrating segment20 with the structural material. Once the structural material cures, theconnector 10 a is effectively anchored within the first structural wythe60 and the insulation wythe 70 is anchored to the structural wythe 60 bygroove 72.

The connector 10 a is then pushed or driven through the insulation wythe70 and into the first structural wythe 60 while the structural materialis still unhardened. The pointed tips 27 a on the connector 10 a areconfigured to facilitate passage of the connector 10 a through anypreformed holes or to cut through the insulation when there are not anypreformed holes in the insulation wythe, thereby facilitating theinsertion of the connector 10 a in either event. In order to insert theconnector 10 a to a desired depth, it may be necessary to apply adriving force to the wall 40 a, 40 b of the connector 10 a. This drivingforce may be applied by hand or with a tool, such as a hammer or mallet.The connector 10 a is inserted through the insulation wythe 70 until theflanges 44 a protruding away from the circular sidewalls 14 a engageagainst the insulation wythe 70, thereby indicating the desired depthhas been reached. Accordingly, the flanges 44 a may be formed of anysuitable structure for orienting the connector 10 a within theinsulation wythe 70 at a predetermined depth.

As the connector 10 a is inserted through the insulation wythe 70, therecesses 45 a between the pointed tips 27 a may receive rebar 62 orother reinforcement that may be present in first structural wythe 60.

Once the connector 10 a is properly oriented within the insulation wythe70, the structural material of the first structural wythe 60 flows intoand engages around pointed ends 26 a, recesses 45 a, a portion ofsidewalls 14 a, and ribs 14 b of the first segment 20 a of the connector10 a. These and other structures anchor the connector 10 a. Vibration ofthe first wythe and/or movement of the connector 10 a may be necessaryto ensure adequate engagement of the penetrating segment 20 a with thestructural material. In addition, vibration and/or movement may assistin engaging rebar 62 or other reinforcement within recesses 45 a. Oncethe structural material cures, the connector 10 a is effectivelyanchored within the first structural wythe 60.

After the first structural wythe 60 has achieved an adequate level ofhardness or strength, a second wythe of structural material is pouredover the surface of the insulating wythe 70 to form the secondstructural wythe 80, as shown in FIGS. 4A-4B. The depth of the secondstructural wythe 80 should be such that it completely, or at leastsubstantially, engulfs the head 40 a, 40 b of the connector and engagesholes 46 a or other anchor formed in the second segment 22 a of theconnector 10 a, thereby providing an adequate anchoring effect of theconnector 10 a within the second structural wythe 80. The material ofstructural wythe 80 flows into groove 72 to anchor structural wythe 80to insulation wythe 70. The flange 44 a also aids in preventing thehardened second structural wythe 80 from collapsing against the firststructural wythe 60 when hardened and tilted up or otherwise positionedfor use.

FIG. 5B shows the use of dovetail shaped grooves 72 formed on the majorsurfaces of the insulating wythe 70. The material of the structuralwythes 60, 80 flows into grooves 72 and forms a mechanical bond betweenthe structural wythes 60, 80 and the insulation wythe 70. Grooves onopposite major surfaces of the insulation wythe 70 may be formedcongruently, as shown in FIG. 5B or may be offset or staggered as shownin FIGS. 4A-4B.

With the configurations illustrated in FIGS. 4A and 4B or 5A and 5B, itmay be desirable to lay a second insulating wythe over the yetunhardened second structural wythe 80, followed by the insertion ofadditional connectors through the second insulation wythe and secondstructural wythe. Thereafter, a third structural wythe may be cast overthe surface of the second insulating wythe as before. Because of thesimplicity of molding the connectors of the present invention, anadapted connector could be molded that would connect three or morestructural wythes together. Alternatively, the three or more structuralwythes can be held together using overlapping connectors of the typeshown in FIGS. 1-5B.

Any groove configuration which provides a mechanical bond between thestructural wythes 60 and the insulation wythe 70 may be used. FIGS.3A-3C show three suitable groove configurations.

FIG. 3A shows insulation wythe 70 having a transverse or horizontalpattern of grooves 72. The grooves 72 may be spaced at any distance thatprovides an improved mechanical bond between the structural wythes 60,80 and the insulation wythe 70. Preferably, the grooves have a spacingof less than 12 in. on center and preferably less 6.5 in. (on center) or4 in. (on center). As shown in FIG. 4B, the grooves on opposite majorsurfaces of the insulation wythe 70 may be offset to improve the degreeof composite action of the finished structure.

FIG. 3B shows insulation wythe 70 having a grid or diamond shaped groovepattern. The grooves 72 may be spaced at any distance that provides animproved mechanical bond between the structural material 60 and theinsulation wythe 70. Preferably, the grooves have a spacing of less than12 in. on center and preferably less 6.5 in. (on center) or 4 in. (oncenter). As shown in FIG. 4A, the grooves on opposite major surfaces ofthe insulation wythe 70 may be offset to improve the degree of compositeaction of the finished structure. The grooves may be positioned at anyangle, although it has been found that a diamond pattern that is widerthan it is tall provides an improved degree of composite action. Onepreferred shape is a diamond having 60° angles on the horizontal axisand 120° angles on the vertical axis. Another suitable shape is a gridhaving four 90° angles.

FIG. 3C shows insulation wythe 70 having rectangular groove pattern. Thegrooves 72 may be spaced at any distance that provides an improvedmechanical bond between the structural material 60 and the insulationwythe 70. Preferably, the grooves have a spacing of less than 12 in. oncenter and preferably less 6.5 in. (on center) or 4 in. (on center). Asmentioned above, the grooves on opposite major surfaces of theinsulation wythe 70 may be offset to improve the degree of compositeaction of the finished structure.

FIGS. 4A and 4B show a detail of the grooved insulation wythe 70 withgrooves 72 formed on the opposed major surfaces and interlockingsections 61, 81 of the structural wythes 60, 80. Grooves 72 form atleast one shoulder 72 a in the remaining material of the insulationwythe 70. The material of the structural wythes 60, 80 flows into thegrooves and under the shoulder 72 a to form a mechanical engagementbetween the structural wythes 60, 80 and the insulation wythe 70. Thegrooves may be formed by any suitable in-line method during manufactureof the insulation wythe or may formed off-line after manufacture of thematerial of the insulation wythe 70. One suitable method of forming thegrooves is in an off-line step using a router. The groove may be of anysuitable shape including square, dovetail, keyhole or a truncatedteardrop shape.

It has been found that the connectors of the invention are capable ofproviding an assembled composite wall with about 50% to about 100%composite action. It will be appreciated that this is a significantimprovement over prior art connectors that have been found, according toindependent testing, to provide only 10% composite action. One benefitof providing such superior composite action is that it enables loads tobe independently carried by each of the structural wythes. It will beappreciated that this is not possible when the composite action issmall, such as when using the connectors of the prior art, because theshear forces caused by the independent loads could cause the structuralwythes to break away from the composite wall.

The connectors according to the invention preferably provide at leastabout 60% composite action, more preferably at least about 70% compositeaction, more especially preferably at least about 80% composite action,and most preferably at least about 90% composite action.

The amount of composite action that is imparted by the connectors isalso related to their spacing. All things being equal, connectors thatare closer together will yield a composite wall structure having greatercomposite action, while connectors that are farther apart will yield acomposite wall structure having less composite action. Thus, actualcomposite action can range anywhere between about 15% to about 100%.Depending on how much composite action is desired, it will be possible,based on the teachings described herein, to select a spacing patternthat will provide the desired level of composite action. One of ordinaryskill in the art will be able to, based on the strength and compositeaction of the connectors, the strength and thickness of the structuralwythes, the strength and thickness of the insulating wythe, and otherfactors that may be determined to affect overall composite wall action,design a spacing patter will provide the desired composite action.

EXAMPLES

Three structural panels, each having two wythes of concrete and aninternal wythe of polystyrene foam insulation were prepared for testing.The concrete wythes were 3 in thick and the polystyrene layer was 2 in.thick. The polystyrene foam was FOAMULAR F250 (available from OwensComing of Toledo, Ohio) having horizontal dovetail grooves having adepth of 0.5 in.; a base width of 1.0 in.; and a surface width of 0.75in. The grooves were spaced along the length of the board by 6.0 in. (oncenter).

The finished panel was 8 in thick by 8.0 feet wide and 32.0 feet high.The panels included 144 connectors as shown in FIG. 5B in 18 rows and 6columns. The rows were 16 inches on center apart and the connectors within each row were 16 inches on center apart apart.

The panels were supported by a span equal to 31 feet and load tests wereperformed using negative air pressure to simulate uniform wind loading.The panel properties compressive strength of concrete (f′_(c-avg)),modulus of elasticity (E_(c)), modulus of rupture (f′_(R)) and crackingmoment (M_(cr)) were measured for each panel as: f′_(c-avg) E_(c) f′_(R)M_(cr) Panel (psi) (psi) (psi) (lb-in) 1 8,670 5.307 × 10⁶ 698 7.039 ×10⁵ 2 8,120 5.136 × 10⁶ 676 6.812 × 10⁵ 3 7,863 5.054 × 10⁶ 665 6.703 ×10⁵ Average 8,220 5.167 × 10⁶ 680 6.854 × 10⁵

The wall was assumed to be uniformly supported and uniformly loaded andthe was calculated as:Δ=(5ωL⁴)/384 EI

The gross moment of inertia I_(g) was used to calculate the deflectionof the wall panel prior to cracking and the cracking moment of inertiaI_(cr) (PCI Equation 4.8.2 5^(th) edition) was used after cracking,respectively:I _(g) =I _(o) +Ad ²I _(g)=4032 in⁴I _(cr) =nA _(ps) d _(p) ²×[1−1.6×√{square root over (n)}ρ _(p)]I_(cr)=104.2 in⁴

The effective moment of inertia (I_(e)) was calculated using (ACIEquation 9-8, 2002)I _(c)=(M _(cr) /M _(a))³ I _(g)+[1−(M _(cr) /M _(a))³]

LECWall software available from Losch Software of Palatine, Ill. wasused to calculate the deflection in the wall panel. The theoreticalcomposite action at 50%, 60%, 70% and 100% was calculated using theLECWall software and is shown in Table 1 and in FIG. 6. TABLE 1 AverageDeflection Test Data ω Load Deflection at Calculated Composite ActionCurve Fit (lb/ft) (psf) 50%(in.) 60%(in.) 70%(in.) 100%(in.) (in.) 0 0 00 0 0 0.00 50 6 0.22 0.17 0.14 0.06 0.09 100 13 0.32 0.26 0.21 0.11 0.21150 19 0.43 0.35 0.29 0.17 0.33 200 25 0.53 0.44 0.37 0.22 0.46 250 310.63 0.53 0.45 0.28 0.61 300 38 0.73 0.62 0.52 0.34 0.76 350 44 0.84 0.70.6 0.39 0.92 400 50 0.94 0.79 0.68 0.45 1.10 450 56 2.74 0.88 0.75 0.51.28 500 63 3.01 2.52 0.83 0.56 1.50 550 69 3.27 2.75 2.35 0.62 1.74 60075 3.54 2.98 2.55 0.67 2.00 650 81 4.56 3.61 2.97 0.73 2.31 700 88 6.244.89 4 2.5 2.66 750 94 8.41 6.5 5.27 3.27 3.08 800 100 11.19 8.51 6.844.19 3.58 850 106 14.74 10.98 8.73 5.28 4.17 900 113 19.27 13.99 10.986.54 4.85

The invention of this application has been described above bothgenerically and with regard to specific embodiments. Although theinvention has been set forth in what is believed to be the preferredembodiments, a wide variety of alternatives known to those of skill inthe art can be selected within the generic disclosure. The invention isnot otherwise limited, except for the recitation of the claims set forthbelow.

1) A structural foam and composite action concrete wall, comprising: atleast one layer formed of polymer foam including a plurality of groovesformed therein; and at least one layer formed of concrete, wherein saidconcrete layer enters at least one of said grooves and is fixed to saidfoam layer. 2) The structural foam and composite action concrete wall ofclaim 1, further comprising: at least one shoulder formed of polymerfoam adjacent at least one of said plurality of grooves and providing amechanical attachment between said structural foam and said concrete. 3)The structural foam and composite action concrete wall of claim 2,further comprising: shoulders formed on opposing sides of said pluralityof grooves. 4) The structural foam and composite action concrete wall ofclaim 2, wherein said grooves are dovetail grooves. 5) The structuralfoam and composite action concrete wall of claim 2, wherein said groovesare generally cylindrical. 6) The structural foam and composite actionconcrete wall of claim 2, wherein said grooves are generally in theshape of a truncated tear-drop. 7) The structural foam and compositeaction concrete wall of claim 1, wherein said wall is a structural wallmember comprising first and second concrete wythes and a polymer foamwythe therebetween. 8) The structural foam and composite action concretewall of claim 7, further comprising: a plurality of structuralconnectors penetrating said polymer foam wythe and connected to saidfirst and second concrete wythes. 9) The structural foam and compositeaction concrete wall of claim 8, wherein said connector comprises: abody having a penetrating segment configured to reside within the firstconcrete wythe, a trailing segment configured to reside within thesecond concrete wythe, and a mesial segment between the penetration andtrailing segments configured to reside within the polymer foam wythewhen the connector is in use. 10) The structural foam and compositeaction concrete wall of claim 9, wherein said connector body comprises:two sidewalls that are spaced apart and that have a width or diameter; aweb portion extending between the two sidewalls, the web portion havinga thickness that is less than the width or diameter of the sidewalls;and a tapered end configured to facilitate penetration of the connectorthrough an insulating layer and a layer of unhardened structuralmaterial adjacent to the insulating layer. 11) The structural foam andcomposite action concrete wall of claim 9, wherein said connector bodycomprises: a collar for limiting penetration of the connector through aninsulating layer at a predetermined depth. 12) The structural foam andcomposite action concrete wall of claim 9, wherein the sidewalls and theweb portion of said connector body have a substantially I-shaped crosssection within the mesial segment. 13) The structural foam and compositeaction concrete wall of claim 9, wherein the sidewalls of said connectorbody are substantially parallel and the web portion is substantiallyperpendicular to the sidewalls. 14) The structural foam and compositeaction concrete wall of claim 1, wherein said grooves are formed in agrid. 15) The structural foam and composite action concrete wall ofclaim 14, wherein said grooves are formed in a right angle grid. 16) Thestructural foam and composite action concrete wall of claim 1, whereinsaid grooves are formed on both major surfaces of the polymer foamlayer. 17) A composite action structural wall member, comprising: afirst concrete wythe; a second concrete wythe; and a polymer foam wythetherebetween, wherein said structural wall member having deflectionunder load less than the deflection under load of a structural wallmember having composite action in excess of the 50% of the theoreticalmaximum composite action for the structural wall. 18) The compositeaction structural wall member of claim 17, wherein said structural wallmember having deflection under load less than the deflection under loadof a structural wall member having composite action in excess of the 60%of the theoretical maximum composite action for the structural wall. 19)The composite action structural wall member of claim 17 wherein saidstructural wall member having deflection under load less than thedeflection under load of a structural wall member having compositeaction in excess of the 70% of the theoretical maximum composite actionfor the structural wall. 20) The structural foam and concrete compositematerial of claim 17, further comprising: a plurality of structuralconnectors penetrating said polymer foam wythe and connected to saidfirst and second concrete wythe. 21) The structural foam and concretecomposite material of claim 20, wherein said connector comprises: a bodyhaving a penetrating segment configured to reside within the firstconcrete wythe, a trailing segment configured to reside within thesecond concrete wythe, and a mesial segment between the penetration andtrailing segments configured to reside within the polymer foam wythewhen the connector is in use. 22) The structural foam and concretecomposite material of claim 21, wherein said connector body comprises:two sidewalls that are spaced apart and that have a width or diameter; aweb portion extending between the two sidewalls, the web portion havinga thickness that is less than the width or diameter of the sidewalls;and a tapered end configured to facilitate penetration of the connectorthrough an insulating layer and a layer of unhardened structuralmaterial adjacent to the insulating layer. 23) The structural foam andconcrete composite material of claim 22, wherein said connector bodycomprises: a collar for limiting penetration of the connector through aninsulating layer at a predetermined depth. 24) The structural foam andconcrete composite material of claim 22, wherein the sidewalls and theweb portion have a substantially I-shaped cross section within themesial segment. 25) The structural foam and concrete composite materialof claim 22, wherein the sidewalls are substantially parallel and theweb portion being substantially perpendicular to the sidewalls. 26) Aninsulation layer for use as an insulation wythe of a composite actionwall, comprising: a polymer foam layer having first and second opposedmajor surfaces; at least one groove formed in each major surface, eachgroove forming at least one shoulder in the polymer foam layer. 27) Thepolymer foam insulation layer of claim 26, wherein said polymer foamlayer is selected from the group consisting of: extruded polystyrenefoam, expanded polystyrene foam, polyurethane foam, polypropylene foam,polyisocyanate foam, polyisocyanurate foam, and combinations thereof.28) The polymer foam insulation layer of claim 26, wherein said grooveis a square groove. 29) The polymer foam insulation layer of claim 26,wherein said groove is a dovetail groove. 30) The polymer foaminsulation layer of claim 26, wherein said groove is a keyhole groove.31) The polymer foam insulation layer of claim 26, wherein said grooveis a truncated teardrop groove. 32) The polymer foam insulation layer ofclaim 26, wherein said grooves on opposed major surfaces are aligned.33) The polymer foam insulation layer of claim 26, wherein said grooveson opposed major surfaces are offset. 34) A connector for a structuralfoam and composite action concrete wall comprising: a body having apenetrating segment configured to reside within a first concrete wythe,a trailing segment configured to reside within a second concrete wythe,and a mesial segment between the penetration and trailing segmentsconfigured to reside within a polymer foam wythe when the connector isin use. 35) The connector of claim 34, wherein said connector bodyfurther comprises: two sidewalls that are spaced apart and that have awidth or diameter; a web portion extending between the two sidewalls,the web portion having a thickness that is less than the width ordiameter of the sidewalls; and at least one leg portion extending fromsaid web portion wherein said leg portion comprises a tapered endconfigured to facilitate penetration of the connector through aninsulating layer and a layer of unhardened structural material adjacentto the insulating layer. 36) The connector of claim 35, wherein saidconnector body further comprises: a collar for limiting penetration ofthe connector through an insulating layer at a predetermined depth. 37)The connector of claim 35, wherein the sidewalls and the web portion ofsaid connector body have a substantially I-shaped cross section withinthe mesial segment. 38) The connector of claim 35, wherein the sidewallsof said connector body are substantially parallel and the web portion issubstantially perpendicular to the sidewalls. 39) The connector of claim35, wherein said tapered end is larger than said leg portion.